Transformer



' 1,576,280 'S. HORELJCK V TRANSFORMER? Mama 9,19%.

Original Filed Feb, 11. 1922 2 Sheets-Sheet 1 Lay],

A 3 B A LQQr- 1J2]; wil 1% A 7 A'I I 1 VENTOR A TTORNE VJ v 40 o'nda'ry? voltage as before.

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SAMUEL HORELICK, OF PITTSBURGH, PENNSYLVANIA, ASSIG-NOR TO PITTSBURGH IBANSFORMER GOMPANY, A CORPORATION OF PENNSYLVANIA.-

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Application :flled'February 11, 1922, Serial No. 535,954. Renewed August 4, 1925.

To all whom it may-concern:

Be it known that I, SAMUEL Honnmox, a citizen of the United States, residingat. Pittsburgh, in the county of Allegheny and 'State'of Pennsylvania, have invented certain new and useful Improvements in Transformers, of which the following is a specification.

' My invention relates to electric transformers, particularlyadapted for use with. dif-- ferent applied voltages. v

It is a common occurrence in practice to provide a transformer which will be readily an increased orlowered voltage.

adapted for use not only On the circuit for which it may be intended at the time, but also for possible use on a circuit of different vvoltage, or for use on the same circuit with For example, a plant mayhave in use one circuit in which transformation from 22,000 volts to a lower voltage isnbeing carried out and thenhave in use another circuit in which transformation from 33,000 volts to a lower voltage is being carried out, or it may be intended to increase the applied voltage in. a.

22,000 volt system to a 33,000 volt system. In either case in purchasing a transformer,

' it is desirablentdhav'e one which "can readily be used on either the higher or lower voltage,

while deriving the same voltage from the ,secondary winding of the transformer in I each .case. In this inst, nee it has been con1- ano e- P a P ima Win in with e suflicieptnumber of turns adapted to receive 33,000 .yolts for securing the des redsec ondary voltage; and to provide a tap on the primary winding so that when used outfit-522,000 volt circuit, connection will be .madegto bne terminal of the winding and to the tap, thus giving the same sec- In such a case, however, the ampere capacity of ,4; of the primary vginding must be yi'igreater than the remaining third of the winding to prowide; for? i wlim the-transformer is used'on the 33,000

, volt circuitfthis excess ampere capacity in "and not e cnnnmica'lly used; and .when the two-thirds of the l'winding is unnecessary 9i transformer-is. teen-gun the 22,000 volt cirseen the 22,000 volt circuit. But

, cuit, one-third ofthe winding is out of cirformer were adapted for use on only one of the two above mentioned voltages; yet the convenience and the saving in expense over the purchase of two transformers has been sufficiently great to warrant the'practice above-described.

The mainobject ofmy' invention is to provide a transformer which will answer they above requirements of being adapted for use with a plurality of primary voltages andwhic'h will have a higi efiiciency. in operation when used'with either of the voltages for. Which it is intended. Another 01)- jeci; is to reduce the size of the transformer compared with the size previously required. Another object is to provide a transformer which will be more economical in cost of construction compared with transformers of this-type previously used.- Another object is to provide means for conveniently connecting the windings so that the trans former will be adapted for use with the particular voltage desired at any time, and to also provide convenient means for chang. ing the connections so; as to be adaptedfor usejwith another voltage: Gther objects and advantages'of my invention will be understood from the following description and accompanying drawings which disclose a preferred embodiment of my invention.

Figs. 1, 2 and 3am diagrams of single phaseuse with difi'erent'voltages; Figs. 4 and 5 transformer windings adapted for are diagrams of transformer windings for I Figs. 6 and 7 are diagrams of transformer windings for a three phase circuit showing the provisionof means for making the con nect ons .as required for the particular voltage on the circuit -on which the'transv former is to beusedr p p ,7 In the app11cationof=my invention here an rereceo particularly described, it is assumed that the lower voltage {or which the transformer is to be adopted is'two-thircls of the higher "voltage, as in the case of the 22,000 and 1 i 33,000 volt, circuit; but'my invention is like- Wise eppliccble to other ratios of voltages, as will be understood by those skilled in the arti My invention is here described as epplied to the primary windings of ct tm11sformer, but may likewise be epplieil to the secondary "windings and may likewise be applied to special cases such as tonutotransformers. In the particular case here considered, most edmntag'couere'snlts are ohteined by sub-dividing the primary winding into our main divisions or sections. Two of these sections will be similar to each other and adapted in this instance .to each receive onethird of the applied voltage, or 11,000 volts in this particular case are assumed.

In Fl 1 of: the drawings these "fiWOSQC- tions are indicated as sections A, A. reincining portion oi} the primary Winding will constitute two other main d visions or sections 13, B. Each of these sections will be adapted to receive 11,000 volts, hot the ampere capacity of ezich may he crude one hell? of that of the sections A, A. The

1 secondary Winding is indicated generally are,

When it is desired to use the trnnslormer on. the high voltage circuit, the tour secv tions of the primary winding .Will con- F nected as shown in Fig. 2, the sections A,

A, of largeremperc capacity being connected in series "with each other and in series with the sections B B of the smaller ampere cal pacify, but with the latter windings connected in parallel with each other. firth this connection of the parts or sections, and with say a primary voltage of 38,000 volts applied to the windings, it will be seen that each section of the primary is nth ed to its full volt and ampere capacity, Thus there will loo 11,000 volts on each section A, A, each of which sections is adapted to carry the full amperage required; and each scotion B B" will be subjected to 11,000 volts 59 nndencii scction adapted to carry only oneheifer the total ainpernge by reason oithose sections being connected in parallel with each other.

When it is desired to use the transformer on thelower primary voltage of 22,000 volts,

the primary sections will be connected as shown in Fig. 3. In this case, each section A A of larger current capacity is connected 5 in series with each other across the primary circuit and each section 13 B of the smaller currentcopecity is connected in series with.

each other across the primary circuit and a cross connection may, if desired, be mace at the connections between the sections. The

windings may be considered as having one The of the larger current council? sections", such as A, connected pernl el 1 1 a lower current capacity section B can 1 znese windings both connected in series 'v c'h the other two sections which letter are connected in parallel with each other. in this ease-such section is subjected to 11,000 volts, but the increased current capacity which is necessary with the lower primary voltage is taken care of by the windings supplementing each other hv reason their parallel connection. The total ampere capacity of the windings should 1301? be approximately 50% greater than when the higher primary volt go was used and itwill be evident that; this in creased current. capacity is provided for he nose the sectionef A. will carry the seine orrentcs before, but as the sections l3 l3 eve one-half the current capacity oi the sections A, A, the total current capacity oi the windings will evidently be 50%"n1'ore than inthe case when the connection for the higher voltage was used. The inoptn'lence, rcectanco and resistance of the scctions shonld of course he so related to each other as to cause the total current to be divided in the desired proportion between the sections when connected in para lel.

It will'elso, be on erent that when the lower voltage is uscc, all s ctions of the windings are utilized at full voltage and nmpere'capecity, which condition was also present when the sections were connected for use with the higher voltage.

With the above sub-division of the primary windings in sections or the voltage and current capacity referred to, it is clear that under each condition there no section orpart of the winding which is not used and it is also true that undcreach condition there is no excess capacity of the windings which is not used economically and to advantage;

and by reason of the above relationship and construction of the windings, it is obvione that the total size of the coils or winch ing and the space occupied by them is much less than in prior practice Where a necessary excess current capacity of two-thirds of the WlZMilHg '\V&S requircdva'ind a third portion which on the lower voltage was not used at all. The smaller total size of the windings obtained by use of my invention also permits acorrcspondiugly reduced size of the transformer core. The use oi the smaller core correspondingly reduces the core. losses both at no load and full load andtlins rcsults in a higher transformer cllicicnc and increased efiiciency may also he obtained due to reduction of copper losses, while at the some time permitting the use or n suuxller transformer as regards winding and core than heretofore required. My invention thus attains. the double advantage cl securing higher ellicicgicy and a reduction in the size end cost oil" inenufactm'e compared with allel-with the anther two setmi'zs conneaztec'i 52:: two secaiozis of larger current capacity in series with each other, vbecnnnnected in amiss with each other 19 4. A igmns'former for caifieren' v=a3t'ages in in series. Wi'-h the uizher two Sections in I the ratio of two to three mmprising a wfindpumiiel and may aiss be connected with two 5 ifig divided in four sections each having the file sections in with web other and same number of turns km) 0% amid. i sh ilk-e M1191 two sectons cm".-

with 4 ch other,

k JEL HOHM. 153K,

SAIEL 

